selling Blood Marrow

Interesting piece on the legality of selling bone marrow. You can't sell organs in the US, but you can sell sperm, blood, platelets, eggs, etc. So if you are using the bone marrow stem cell from your blood harvesting method, how is that different from selling blood? Should it be different? Intriguing questions. Donation is a bit of a pain, so why not be compensated? On the other hand that once again makes it more likely that the procedure will be too expensive for many people who can't pay a "finders fee."

http://www.nejm.org/doi/full/10.1056/NEJMp1114288?query=TOC